"These have been breakthrough therapies," said Dr. Joseph P. Ornato, a cardiologist and emergency medicine specialist who is medical director for the City of Richmond, Va. "But the hooker is that even the best of the clot buster drugs typically only open up 60 to 70 percent of blocked arteries — nowhere close to 100 percent."

The drugs also make patients vulnerable to bleeding, Ornato said.

One in 200 patients bleeds into the brain, having a stroke from the treatment meant to save the heart.

The other way is with angioplasty. Cardiologists say it is the preferred method under ideal circumstances.

Stents have recently been questioned for those who are just having symptoms like shortness of breath. In those cases, drugs often work as well as stents.

But during a heart attack or in the early hours afterward, stents are the best way to open arteries and prevent damage. That, though, requires a cardiac catheterization laboratory, practiced doctors and staff on call 24 hours a day. The result is that few get this treatment.

"We now are seeing really phenomenal results in experienced hands," Ornato said. "We can open 95 to 96 percent of arteries, and bleeding in the brain is virtually unheard of. It's a safer route if it is done by very experienced people and if it is done promptly. Those are big ifs."

Currently, 30 percent of patients who are candidates for reperfusion do not receive it, and of those who do, only 18 percent are treated with angioplasty, said Dr. Alice Jacobs, director of the cardiac catheterization laboratory at Boston University School of Medicine and a past president of the American Heart Association. Of the nation's 5,000 acute care hospitals, Jacobs said, only 1,200 provide angioplasty.

Most hospitals, she said, cannot offer angioplasty because they do not have enough patients for a team of doctors to maintain their skills.

An obvious solution would be sending patients to the nearest hospital that can provide angioplasty as quickly as possible. But that is not always easy, Jacobs said, because hospitals do not want to lose cardiac patients.

A major reason, she said, is financial. Hospitals are reimbursed by Medicare according to an index that measures the acuity of medical conditions they treat. "If your cardiac patients are transferred, your acuity index goes down, which lowers overall Medicare reimbursement for other problems like pneumonia and renal disease," Jacobs said.

It is also difficult for patients who live in rural areas. Minnesota is experimenting with a program using helicopters to transport patients quickly. But for most rural patients elsewhere, angioplasty is almost an impossibility.